Along with continual increase of safety consciousness in modern lives, safety requirement of inhabitant environment becomes higher and higher. However, there are still some hazards, such as fires, that can not be completely spared. If fires can be put out immediately when they happen, some misfortunes can be avoided.
Fire extinguishers are indispensable equipment to secure lives and properties of respective families. But the user usually does not know how to operate the fire extinguisher in emergency such that its fire extinguishing function can not be exploited. Moreover, fog usually pervades the fire site such that there is not enough light for the operation guide on the fire extinguisher to be seen clearly. Good chance to put out the fire is thus lost such that the fire can not be put out betimes.